Field
The present application relates to an optical transceiver, in particular, the application relates to an optical transceiver implementing with a circuit board mounting electronic circuits and a plug board electrically coupling the electronic circuits on the circuit board with a host system, where the plug board is physically independent of the circuit board.
Related Background Art
One type of multi-source-agreements (MSA) has defined that the circuit board for mounting electronic circuits is independent of a plug board having an electronic plug to couple with a connector prepared in the host system to communicate with the host system, because, as functions requested for the optical transceiver becomes complex and power consumption of the transceiver increases, the count of lead pins provide in the plug and the connector increases, and sometimes exceeds one hundred. The accuracy of the physical dimension required for such a plug and a connector enhances. When an optical transceiver installs such a precisely formed plug board integrated with a circuit board unnecessary for such fine dimensions, the cost of the optical transceiver becomes high. In another application, an optical transceiver is requested that a plug board thereof is made of resin to secure high frequency performance thereof. In such an application, the plug board is inevitable to be independent of the circuit board. Accordingly, advanced optical tranceivers usable in applications where a huge capacity of information is transmitted in extremely high speed often provide the plug board independent of the circuit board.
However, when two boards have respective thicknesses, that is, the plug board is necessary to have a thickness fit to the optical connector in the host system, the dimensions of the plug board are strictly and precisely determined in the MSA to secure the coupling between the plug in the optical transceiver and the connector in the host system, while, the circuit board is likely to be formed thinner because of the material cost, and the assembly of the plug board with the circuit board becomes complex. In particular, when two boards are assembled by the reflow soldering, two boards are necessary to be held in a level. When two boards are assembled in imbalance, namely, assembled in a tilted angle, the process to install two boards within the housing may cause stresses to the boards.